The BRICS have come to realize that it is not a good idea to keep all their eggs in one (currency) basket. Especially a basket being handled in the way that the US govt has been handling the dollar.

Also, with sanctions against Iran preventing them from trading for oil in USD, they realize the need for alternatives for the next time the Govt decides to throw a tantrum and try to tell the rest of the world that they cant trade with another sovereign nation.